Car body surface treatment device

ABSTRACT

In a simple car body surface treatment device, the car body (16) is brought into and taken out of the treatment bath (1) exclusively by rotation of a revolving device (2). The car body (16) arranged on a loading carriage (11) is detachably connected to the revolving device (2). In addition, conveyors (12, 13, 17, 18) are provided for carrying the loading carriage (11) on to or away from the revolving device (2). The device is characterized by the conveyors (12, 13, 17, 18) being located outside of the treatment bath (1). The conveyors (17, 18) located in the area of rotation of the revolving device (2) may be moved out of and into this area.

BACKGROUND OF THE INVENTION

The invention relates to a surface treatment device for one or more carbodies, having a rotating device, to which at least one car body mountedon a loading carriage is detachably connectable and which dips the carbody into a treatment bath by rotation and in turn takes it out of saidbath by a rotation, as well as having conveyors for carrying the loadingcarriage on to or away from said rotating device.

A device for the surface treatment of car bodies, which are dipped byrotation into a treatment bath and are taken out of same bycounter-rotation, is known from GB 2 229 381. In this known device, acar body is securely connected to a loading pallet. This unit composedof a loading pallet and car body mounted thereon is fitted on to aroller carriage. This roller carriage is equipped with non-drivenrollers which enable a displacement to the side of the car body'slongitudinal axis. By means of such a non-driven roller carriage, theloading pallet is conveyed from the treatment bath to other processingstations.

The entire composite structure, consisting of the car body, loadingpallet and roller carriage, is pushed on to a mount which is attachedabove each treatment bath. This mount has a rotation axis perpendicularto the car body's longitudinal axis or parallel to the direction ofconveyance. By rotation around the rotation axis through 180°, theentire composite structure of car body, loading pallet and rollercarriage can now be dipped into the treatment bath. During the immersionoperation, his mount and the unit of car body, loading pallet and rollercarriage are connected together by means of locking pins.

A conveyor belt extending across several treatment stations and theirtreatment tanks is used to transport the car bodies or roller carriages.These treatment stations are laterally adjacent. The conveyor belttransports the roller carriages, on which a loading pallet with its carbody is respectively fitted, from treatment tank to treatment tank.Vertically positioned pallet pieces, which make contact with the rollercarriage, are fitted on the conveyor belt for this purpose.

This type of device for the introduction of a car body enjoys theadvantage that a simple mechanism is used to minimize the extent towhich the treatment fluid in the treatment bath is spilled, in that thecar body is rotated into the treatment bath via the front or the rearside. During the rotation process, the quantity of air entrapped withinthe car body is continuously able to escape from the car body's windows.

This device's structure is relatively complex and only suitable forsmall-scale systems. When a car body is immersed, the next body mustwait until the first body's process time has elapsed. This process timeamounts to as much as three minutes in the case of individual processstages and is even longer in the case of cathodic dip painting.

DE 43 04 145 C1 describes a device of the named class in which a carbody is also dipped into a treatment bath by means of rotation. In thecase of the immersed car body, it is also possible for another car bodyto be fitted on to this rotating device and to be detachably connectedor for it to be able to pass over the rotating device.

In the known device, a loading carriage is used to receive and fix thecar body. The loading carriage and car body are pushed on to therotating device by means of one or more driven rollers and aredetachably connected thereto by means of fixing devices. The rotatingdevice is attached above the treatment bath and comprises a rotationaxis transverse to the direction of conveyance of the car bodies. Thecar body is now introduced by rotating the rotating device in such amanner that the car body is dipped via its front or rear side into thetreatment bath. One or more of the rollers on the upper and lower sidesof the rotating device are respectively driven so that the loadingcarriages and car bodies can be passed along.

This design suffers from the disadvantage that the rotating devicecomprises a plurality of mechanically mobile parts (guidance rollers androllers for moving the loading carriage) which accumulate a significantamount of dirt as a result of the painting process and which contaminatethe paint bath with dried paint residue. Because the rollers arerepeatedly dipped in the treatment bath, their functioning cannot beensured even after a short period of time.

SUMMARY OF THE INVENTION

The technical problem upon which the invention is based is to provide acar body surface treatment device in which accumulation of dirt on themechanically mobile parts is largely avoided when the car bodies areintroduced by rotation.

This technical problem is solved in a device according to the class inthat the conveyers are located outside the treatment bath and theconveyers located within the rotating device's area of rotation can bemoved out of and into this area.

The invention is based on the idea of arranging the conveyers used forintroducing and removing the loading carriages with the car bodiessecured thereto, as well as the drive and guidance rollers, conveyerbelts etc. in such a manner that they themselves do not dip into thetreatment tank during car body treatment, i.e. they are securedseparately from the loading carriage and rotating device. As a result,substantial dirt accumulation and any malfunctions affecting the driveand guidance rollers as well as any necessary conveyer belts can belargely prevented. As a result of the mobile design of the conveyers,which are located in the area of rotation of the rotating device withthe car body fitted thereon, these parts can also be guided out of, andif necessary back into, the area of rotation. A rotary movement of therotational device can therefore take place in an unlimited manner in itsangle of rotation. The retractable and protractable conveyors also makeit possible to pivot the car body fitted on the rotational device in itsimmersed state, thereby allowing the entrappad air bubbles to escapemore effectively, which leads to a higher-quality coating result.

By guiding the movable conveyors out of the rotating device's area ofrotation during the rotational raising movement, an accumulation of dirton the transport or conveying means caused by paint flowing down the carbody is minimized and hence the risk of dirt accumulating inside thetreatment bath due to residual paint dried on the conveyors is reduced.

The design input is likewise substantially simplified when designing therotating device, resulting in lower production costs and making it lessexpensive to control and maintain the system.

In particular, the simple structure of the device according to theinvention makes it possible to increase the cycle rate at which the carbodies are introduced into the treatment bath by the fact that it isalready possible to start conveying another car body over the treatmentbath even though the preceding car body has not yet been completelyimmersed, thereby increasing the capacity of the entire system (severalbaths connected in series). All in all, the immersion process isimproved by these measures in terms of achievable coating quality andeconomy.

The conveyors advantageously comprise guidance and driven drive rollersin order to carry the loading carriage and the car body mounted thereonon to or away from the rotating device. As a result of this simplestructure, a loading carriage is guided between a number of facingrollers, whereby one or more of these rollers are driven, causing theloading carriage to be moved by transfer of friction. This also makes itpossible for a loading carriage to be passed on from one treatmentstation to the next in a simple manner.

Since the conveyors located within the rotating device's area ofrotation can be guided out of or into the area of rotation as required,it is possible to pivot an immersed car body in an unlimited way. Asalready mentioned, residual paint and dye, which contaminate the bath,are also largely avoided in that the conveyors can be moved away fromthe dripping area when the car body which has already been treated israised.

A very simple and inexpensive design solution for guiding the conveyorin and out is to attach this conveyor to a sliding means, such as ahydraulic ram, electrical drive or chain drive, in a slidable manneracross the treatment bath on facing sides, allowing the loading carriageto be guided or passed on with its edge regions on the guidance anddrive rollers. It is just as suitable to rotate the conveyors away, inwhich case hydraulic, pneumatic or electrical drives are possible.

In order that the rotating device and the loading carriage detachablyconnected thereon can be easily rotated, it is particularly advantageousfor the conveyors' individual guidance and drive rollers to be eachfitted with a raised edge at least on one roller side, causing theloading carriages to be guided and driven, though the loading carriageguided thereon is still able to "rotate away in an upwards direction"without hindrance.

So that the air bubbles entrapped within the immersed car body cancompletely escape at the car body's rear or front side, it isparticularly advantageous for the bodies to be immersible into thetreatment bath by rotation through up to 210°, with the conveyorslocated in the area of rotation being retractable or protractable, ifnecessary.

If for example, the configuration of the individual treatment bathsmakes it desirable to dip the car bodies into the treatment bath or toguide them out of it by rotation through 360°, it is particularlyadvantageous to arrange in a movable manner all those conveyors locatedwithin the area of rotation.

In the device according to the invention, it is advantageously possiblefor the car bodies, in their immersed state, to be able to be rotatedthrough up to 30° in both directions of rotation so as to enable theentrapped air bubbles to escape more effectively.

The conveyors with their guidance and drive rollers are advantageouslymovably arranged outside the rotating device so that during theimmersion operation, they can be guided into a position which enablesone or more successive car bodies to pass over the tank or treatmentbath, making it possible to increase further the cycle rate at which thecar bodies are to be treated, with the treatment baths arranged insuccession.

If the rotating device is fitted with fixing and locking means fordetachably securing a loading carriage not only on the upper side butalso on the lower side, it is possible, when a car body is immersed, tofit another car body on the same rotating device by means of theconveyors attached to the edge of the treatment bath. Only thoseconveyors attached above the treatment bath are advantageously requiredin the rotating device according to the invention in order to treat thesurface of several car bodies simultaneously, rather than treating thesurface on the upper and lower sides respectively, as is the case withthe known devices.

The necessary combination of spraying and dipping processes is madepossible by the device according to the invention in which the knownloading carriage technique is used; this applies both to thepretreatment of the car bodies and to the dip-painting thereof.

To portray and explain the invention more effectively, an exemplaryembodiment will be described and explained in further detail withreference to the enclosed drawings as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic longitudinal section of a treatment tank with acar body surface treatment device according to the invention, having arotating device,

FIG. 2 shows a schematic cross section of the device according to theinvention as shown in FIG. 1, and

FIG. 3 shows a horizontal projection of the device according to theinvention, with a rotating device and conveyors which can to an extentbe positioned; the car body is not depicted in this top view.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1, in the device according to the invention, a rotatingdevice 2 is attached above a treatment tank for treatment bath 1.Rotating device 2 is supported at the left and right of the ends of arotation axis 3 by bearing brackets 4 on a container wall 5. Conveyors,which are formed as guidance rollers 12, drive rollers 13 and slidableguidance and drive rollers 17 and 18, are located above treatmenttank 1. Drive rollers 13 are driven by an electric motor 15 by means ofa conveyor belt 14. In the state shown in FIG. 1, a loading carriage 11with a car body 16 secured thereon is carried on to rotating device 2 bymeans of non-driven guidance rollers 12 and driven drive rollers 13.Other guidance rollers 12 at the side above treatment bath 1 andslidable guidance and drive rollers 17, 18 are attached in the directionof conveyance ahead of car body 16 and loading carriage 11.

As schematically shown in FIG. 2, rotating device 2 is fitted with aframe 8, fixing devices 9 attached thereon and locking devices 10.Bearing brackets 4, with which the ends of rotation axis 3 engage, alsorender apparent the way in which rotating device 2 is supported.Rotation axis 3--as already mentioned--is driven via a gear 7 by a drive6.

Loading carriage 11, shown here without car body 16, engages withfork-shaped fixing device 9 by means of its longitudinal members and isguided as a result. Fixing devices 9 are used for laterally guidingloading carriages 11 while they are being carried on to rotating device2. Locking devices 10 comprise a slidable pin which respectively engageswith a recess provided for this purpose at the side within loadingcarriage 11. Locking device 10 may, however, also be fork-shaped indesign, allowing the fork to engage with a corresponding recess whenloading carriage 11 is interlocked.

In the horizontal projection represented in FIG. 3, the regulardistribution of guidance rollers 12 and drive rollers 13 as well as ofslidable guidance rollers and drive rollers 17 and 18 becomesparticularly clear. The distances of these rollers 12, 13, 17 and 18 areobtained by the schematically shown length of loading carriage 11,causing this carriage to be driven and guided at all times duringtransportation. In this exemplary embodiment, only guidance and driverollers 17 and 18, which are located ahead of non-immersed rotatingdevice 2 and within its area of rotation, i.e. around rotation axis 3,are designed to be slidable. It is, however, conceivable for rearrollers 12 and 13 to be slidably designed as well if rotating device 2is rotated through 360°.

The operational mode of this embodiment of the device according to theinvention will now be explained.

Before the surface treatment or the treatment of car bodies commences asa composite structure of several treatment stations, car body 16 issecurely connected to a loading carriage 11. Loading carriage 11 istransported on to rotating device 12 via guidance rollers 12 and bymeans of drive rollers 13. The loading pallet of loading carriage 11 isguided by the side guides of fixing device 9, which are attached toframe 8 of rotating device 2.

If loading carriage 11 is correctly positioned on rotating device 2,geared motor 15 of drive rollers 13 is brought to a halt and the loadingcarriage is securely connected to rotating device 2 by locking devices10. This takes place by squeezing locking devices 10 or by fasteningthem with pins; these locking devices engage inside loading carriage 11.

Movable guidance rollers 17 and movable drive rollers 18 above theforward area of treatment tank 1 are then guided out of the area ofrotation of rotating device 2, i.e. slid outwards by hydraulic rams inorder to make it possible for rotating device 2 to rotate car body 16subsequently by up to 180° or more. During the rotating operation,rotating device 2 with loading carriage 11 and car body 6 securedthereon dips into treatment bath 1. On completion of the rotationoperation, car body 16 is now completely immersed within treatmentbath 1. The rotation has caused the previous upper and lower sides ofrotating device 2 to be changed around.

If the intention is to dip car body 16 into treatment bath 1 in thereverse direction of rotation, movable conveyors 17 and 18 are locatedabove the rear area of tank 1.

If a rotation through more than 180° is desired, movable guidance anddrive rollers 17 and 18 both above the front and rear areas of treatmenttank 1 can, depending on the required angle of rotation, be designed insuch a manner that they can be guided out of and into the area ofrotation. As a result, the entire area above treatment tank 1 is leftclear for a rotary movement in any direction and any angle of rotation.

As soon as the immersion operation or the rotary movement allows aposition in which guidance rollers 17 and drive rollers 18, which can beguided out of and into the area of rotation, no longer impede the rotarymovement, these rollers 17 and 18 are correspondingly guided back intotheir initial position. It is now possible for a subsequent car body 16on a loading carriage 11 to pass over treatment tank 1.

If a pivoting of car body 16 in its immersed state is desired, guidancerollers 17 and drive rollers 18, which can be guided out of and into thearea of rotation, can be guided into and out of the area of rotation inorder to enable car body 16 to pivot in both directions of rotation.

In a further exemplary embodiment not shown here, not only the upper butalso the lower side of the rotating device is provided with a fixingdevice 9 and a locking device 10. When car body 16 is immersed, it isthen possible to fix a further loading carriage 11 on what is now theupper side. By rotation through another 180° or by rotating back through180°, the new mounted car body is dipped into treatment bath 1 and atthe same time, the treated car body is guided out of this bath.

I claim:
 1. A device for the surface treatment of one or more car bodies(16), comprisinga rotating device (2) to which at least one car body(16) mounted on a loading carriage (11) is detachably connectable andwhich dips said car body (16) into a treatment bath (1) by rotation andin turn guides said body out of said bath by rotation, conveyor means(12, 13, 17, 18) for carrying said loading carriage (11) on to or awayfrom said rotating device (2), said conveyor means (12, 13, 17, 18) areattached outside said treatment bath (1), and said conveyor means (17,18) located within the area of rotation of said rotating device (2) canbe moved out of or into said area of rotation.
 2. A device according toclaim 1, wherein said conveyor means comprise guidance rollers (12) anddrive rollers (13).
 3. A device according to claim 1, wherein saidconveyor means (17, 18), which can be guided into or out of said area ofrotation are slidable by a positioning means.
 4. A device according toclaim 1, wherein said conveyor means (12, 13, 17, 18) comprise rollerswhich have a raised edge at least on one roller side, so that saidloading carriages (11) can be guided and driven.
 5. A device accordingto claim 1, wherein said car body (16) is immersible into said treatmentbath (1) by rotation through more than 210° and can in turn be guidedout of said bath by a rotation.
 6. A device according to claim 1,wherein said car body (16) is immersible into and can be guided out ofsaid treatment bath (1) by rotation through 360°.
 7. A device accordingto claim 1, wherein in its immersed state, said car body (16) isrotatable in both directions through up to 30° in order to enableentrapped air bubbles to escape.
 8. A device according to claim 1,wherein said conveyor means required for carrying said car bodies (16)and designed in the form of guidance rollers (17) and drive rollers (18)are movably arranged outside said rotating device (2) such that duringthe immersion operation, they can be guided into a position whichenables one or more successive car bodies (16) to pass over said bath(1).
 9. A device according to claim 2, wherein said conveyor means (17,18), which can be guided into or out of said area of rotation areslidable by a positioning means.
 10. A device according to claim 2,wherein said conveyor means (12, 13, 17, 18) comprise rollers which havea raised edge at least on one roller side, so that said loadingcarriages (11) can be guided and driven.
 11. A device according to claim3, wherein said conveyor means (12, 13, 17, 18) comprise rollers whichhave a raised edge at least on one roller side, so that said loadingcarriages (11) can be guided and driven.
 12. A device according to claim2, wherein said conveyor means required for carrying said car bodies(16) and designed in the form of guidance rollers (17) and drive rollers(18) are movably arranged outside said rotating device (2) such thatduring the immersion operation, they can be guided into a position whichenables one or more successive car bodies (16) to pass over said bath(1).
 13. A device according to claim 3, wherein said conveyor meansrequired for carrying said car bodies (16) and designed in the form ofguidance rollers (17) and drive rollers (18) are movably arrangedoutside said rotating device (2) such that during the immersionoperation, they can be guided into a position which enables one or moresuccessive car bodies (16) to pass over said bath (1).
 14. A deviceaccording to claim 4, wherein said conveyor means required for carryingsaid car bodies (16) and designed in the form of guidance rollers (17)and drive rollers (18) are movably arranged outside said rotating device(2) such that during the immersion operation, they can be guided into aposition which enables one or more successive car bodies (16) to passover said bath (1).
 15. A device according to claim 5, wherein saidconveyor means required for carrying said car bodies (16) and designedin the form of guidance rollers (17) and drive rollers (18) are movablyarranged outside said rotating device (2) such that during the immersionoperation, they can be guided into a position which enables one or moresuccessive car bodies (16) to pass over said bath (1).
 16. A deviceaccording to claim 3, wherein said positioning means is selected fromthe group consisting of a hydraulic ram, electrical drive, and chaindrive.
 17. A device according to claim 9, wherein said positioning meansis selected from the group consisting of a hydraulic ram, electricaldrive, and chain drive.